Procedure Identify the side(s) with the suspected tension pneumothorax by absence of breath sounds and lack of chest wall movement on examination in combination with hemodynamic and/or respiratory instability or cardiac arrest The trachea may be deviated Restrain the child, if necessary Cleanse an area in the second or third intercostal space, midclavicular line with antiseptic solution Recent studies suggest that the fourth or fifth intercostal space, anterior axillary line, may be easier to perform and less likely to injure major vessels Insert the over-the-needle catheter perpendicular to the skin into the selected intercostal space being careful to go immediately over top of the rib in order to avoid the intercostal neurovascular bundle that runs along the inferior portion of the rib Listen for a rush of air, if the environment allows, confirming release of the tension pneumothorax Advance the catheter into the pleural space, and remove the needle Alternatively, the over-the-needle catheter can be attached to the syringe filled with a few milliliters of sterile saline or water prior to introducing the needle into the pleural space Advance the syringe attached to the over-the-needle catheter into the pleural space while aspirating gently on the syringe, observing for the presence of bubbling in the syringe, indicating that the pleural space has been entered and a pneumothorax is present Remove the syringe to release the pneumothorax Immediately after completing the needle thoracostomy, prepare for chest tube placement Air can be withdrawn using a large syringe and threeway stopcock, but this is not necessary; the “tension” is relieved with catheter placement leaving it open to the air The catheter should not be closed by attachment of syringe or stopcock—this would allow air to reaccumulate in the pleural space and pleural pressure to increase INSERTION OF A CHEST TUBE Indications Evacuation of a pneumothorax Drainage of a hemopneumothorax, symptomatic empyema, or large pleural effusion Esophageal rupture with gastric leakage into the pleural space